Efficacy Of Green House Gas Forcing Compared To Solar Forcing

Guest post by Bob Irvine

SUMMARY

This paper outlines an idea or hypothesis that should be discussed. This idea has the huge advantage of being supported by all the available data both from over the last thousand years or more, the last 60 or 70 years and the last 20 years.

We have a chance here to solve the global  warming debate and standoff.  It is quite possible that both sides of the debate have some truth on their side.  I believe there is a strong case that the climate sensitivity or temperature response to a given forcing not only depends on the size of that forcing but also on the nature of that forcing.  I have attempted to mount a case for the idea that a given  LONG WAVE  GHG forcing will have considerably lower temperature response than a similar SHORT WAVE solar forcing.

The alarmists may well be correct.  There is a lot of evidence from the Last Glacial Maxima and Volcanoes and other areas that climate sensitivity is quite high (about 0.8, i.e. requil. T=0.8xrF).  Certainly, this can be seen on geological scales.  These estimates are based on Short Wave Solar Forcings.  The trouble starts when they try to apply these high sensitivities to the enormous increase in Long Wave GHG forcing that has occurred in the last 60 or 70 years.  They mistakenly assume that a given GHG forcing will have the same equilibrium temperature response as a similar Solar Forcing and then find it difficult or impossible to make the meagre temperature response over recent years fit their high sensitivities.

The riddle is neatly solved if we accept the concept of “Effective Climate Forcing”. In other words, we accept that a given Long Wave GHG Forcing has a lower climate sensitivity than a similar Short Wave Solar Forcing. It is in fact intuitively unlikely that these two forcings have the same efficacy as is assumed by the IPCC and others.

INTRODUCTION

The efficacy of a given forcing is an estimate of its efficiency in provoking an equilibrium temperature response in the earth’s system. The IPCC and others assume that a given change in GHG forcing will produce a temperature response that is approximately equal to the temperature response from a similar change in solar forcing.

That this is not necessarily the case is discussed in the literature. Joshi et al 2003, Hansen and Nazarenko 2004 and Shine et al 2003 all conclude that the same forcing can have a different temperature response depending on its nature or geographic location.

Forster and Taylor 2006, “Climate Forcings and Climate Sensitivities Diagnosed from Coupled Climate Model Integrations “ make the case that ”Effective Climate Forcing” is a much more useful way of estimating climate sensitivity than conventional; one size fits all, Radiative Forcing. They make their case succinctly in the following quote;

“Imagine, for example, that the atmosphere alone (perhaps through some cloud change unrelated to any surface temperature response) quickly responds to a large radiative forcing to restore the flux imbalance at the TOA (Top Of Atmosphere), yielding a small effective climate forcing. In this case the ocean would never get a chance to respond to the initial Radiative forcing, so the resulting climate response would be small and this would be consistent with our diagnosed “effective climate forcing” rather than the conventional “Radiative forcing.”

In the quote above a shorter response time at the TOA produces a lower climate sensitivity. Hansen, Sato and Kharecha confirm and support this in their paper “Earth’s Energy Imbalance and Implications”, by saying

“On a planet with no ocean or only a mixed layer ocean, the climate response time is proportional to climate sensitivity. ………..Hansen et al (1985) show analytically, with ocean mixing approximated as a diffusive process, that the response time increases as the square of climate sensitivity.”

If it can be shown that the restoration of the flux imbalance at the TOA is quicker for a perturbation in GHG forcing than it is for a similar perturbation in solar forcing, then this would imply a lower climate sensitivity for GHG forcing than solar forcing.

DISCUSSION

It is in fact intuitively unlikely that the earth’s system would respond in almost exactly the same way to a change in Long Wave GHG forcing as it would to a change in Short Wave solar forcing, as the IPCC and others assume.

It is established physics that Long wave Radiation from GHGs only penetrates the oceans to a depth of a fraction of a millimetre. The oceans are virtually opaque to these wave lengths. Short Wave solar radiation, on the other hand, penetrates the ocean to a depth of 10 meters or more and it is counter intuitive to assume that this established fact would have close to zero effect on flux imbalance restoration times at the TOA.

Despite this matter being pivotal to any understanding of the earth’s climate response to increasing Anthropogenic GHGs (AGHG), I have been unable to find any literature supporting the IPCC’s position that solar forcing and GHG forcing have the same efficacy after the ocean/ atmosphere interface has been considered. The references mentioned by the IPCC in their reports only refer to the global nature of the two forcings and only take into account feedbacks that are related to a temperature response. These do not apply in this case. Basically, the fact that the oceans are opaque to GHGs is due to the nature of the forcing and not accounted for if the feedbacks considered are only related to a temperature response. Similarly, to assume, as the IPCC does, that GHG forcing and Solar forcing have the same “effective climate forcing” simply because they are both global in nature, also, does not take account of the opaqueness of the oceans to the wave length reemitted by GHGs.

The blogosphere does make an attempt at explaining the IPCC’s position. The only defence I am aware of is that the top fraction of a millimetre of the ocean is heated up by the Long Wave Radiation (LWR) reemitted by GHGs. This then acts as a blanket slowing the release of energy from the ocean, thereby effectively warming the ocean by nearly exactly the same amount as a similar solar forcing that penetrates the ocean to a depth of 10 meters or more.

Not only is it highly improbable that these two entirely different mechanisms would have almost exactly the same effect on OHC (Ocean Heat Content), but it can be shown by means of a simple experiment, (Appendix 1), that nearly all the Long Wave GHG energy is returned almost immediately to the atmosphere and space as latent heat of evaporation. It, therefore, has little effect on OHC. It is, also, likely that the restoration of the flux imbalance at the TOA is quicker for a perturbation in GHG forcing than it is for a similar perturbation in solar forcing.

It is apparent that the situation described in the Forster and Taylor (2006) quote above is relevant to GHG forcing. In short, the” Effective Climate Forcing” of a GHG change is likely to be considerably less than the “Effective Climate Forcing” of a similar solar change.

CORROBORATION

It is an intriguing possibility that both sides of the Global Warming debate could be correct to some extent. The IPCC and others estimate climate sensitivity by reference to three factors, none of which apply to climate sensitivity derived from a GHG forcing.

These three factors are;

  1. They use “Absolute Radiative Forcing” instead of “Effective Radiative Forcing” (Forster and Gregory 2006)
  2. They use sensitivities based on Solar Forcing which clearly do not apply to GHG Forcing. For example, sensitivities calculated from the Last Glacial Maxima (LGM) or volcanoes are essentially based on Solar Forcing and, therefore, do not apply to GHG Forcing. (Annan & Hargreaves 2006).
  3. They use feedbacks that are dependent on an initial temperature response and, therefore, do not take account of the opaqueness of the oceans to Long Wave Radiation from GHGs. (All the Global Climate Models , GCMS)

The IPCC and others may have produced some good science that gives reasonably accurate climate sensitivity estimates for a change in solar forcing. Unfortunately, these are unlikely to apply to a GHG Forcing.

Interestingly, Idso 98 uses real world experiments that, largely, do apply to GHG Forcing and their climate sensitivity is considerably lower than the IPCC’s consensus.

The sceptics, on the other hand, are fairly obviously quite correct when they say that the high sensitivities postulated by the alarmists do not fit with the measured temperature record of the 20th and 21st century.

The best way to show this lack of correlation is to compare the amount of energy put into the system by human GHGs, as represented by equilibrium temperature, with actual temperature as measured in the thermometer age since 1880.

The green line in Fig. 1 equates to a sensitivity of 0.8 (rT = 0.8 x rF) which gives an equilibrium temperature increase of 3.0°C for a doubling of human CO2, the IPCC’s central position. In 2010 the difference between the green line and blue line (actual temperature) was an unlikely 1.4°C. If present trends continue, as is likely, that gap would be close to 2.0°C in 5 years’ time.

image

FIG, 1 The IPCC’s upper (purple), central (green) and lower (red) equilibrium temperature predictions using their climate sensitivity to forcing. The forcings were calculated for all the human GHGs using concentrations given in 4AR and the generally accepted conversion formula, rF=5.35xln(C/Co) WM-2 where C is current concentration and CO is starting concentration. These are compared with actual temperature (blue). For comparison purposes all graphs were zeroed in 1880.

NOTE; It is generally believed that equilibrium temperatures are approximately 1.5 times transient temperatures (4AR) and that aerosol cooling has masked any human induced GHG warming. These are the two factors the alarmists use to attempt to explain the gap between reality and the IPCC’s calculated equilibrium temperatures from AGHGs.

There are also major inconsistencies with the Ipcc’s explanation for the warming from 1910 to 1940. Bob Tisdale discusses these inconsistencies at WUWT on the 20th April 2013.

The only realistic explanation for this lack of correlation ( FIG, 1) is that the IPCC’s sensitivities are far too high and that the “Effective Radiative Forcing” for Long Wave GHGs is considerably lower than the “Effective Radiative Forcing “ for Short Wave solar.

APPENDIX 1

This experiment is attributed to Tallbloke and shows unequivocally that Long Wave radiation from GHGs has little or no effect on Ocean Heat Content. Short Wave Solar radiation, on the other hand, penetrates the oceans to a depth of ten meters or more and, therefore, adds significantly to OHC.

Konrad: Empirical test of ocean cooling and back radiation theory

Posted: August 25, 2011 by tallbloke in atmosphere, climate, Energy, Ocean dynamics

68

Some background –

Willis Eschenbach had a guest posting over at WUWT in which he claimed that LWIR could heat Earth’s oceans. Myself and several others on the thread contended that this LWIR was likely to be stopped by the evaporative skin layer and would not slow the exit of heat from the oceans. Numerous requests for empirical evidence to support Willis’s claim only resulted in one inapplicable study used by the “Hockey Team” to support such claims. After several hundred comments without empirical evidence being offered, I gave up reading and designed and conducted an empirical experiment that shows that any effect of backscattered LWIR on the cooling rate of water would be negligible.

What follows is an edited version of the experiment design and results as posted on the WUWT thread. I would encourage others to conduct similar experiments to check my results. The equipment required is not overly expensive and the results can be observed in minutes. The results appear to show the measurable difference between reflecting LWIR back to warm water when it is free to evaporatively cool and when it can only cool through conduction and radiation.

What is required –

– Two identical probe type digital thermometers with 0.1 degree resolution

– Two identical insulated water containers. I used rectangular 200ml Tupperware style containers, insulated on their base and sides with foil and Styrofoam. I cut away the clip on rim from each lid to create a frame to clip down cling film for Test B of the experiment.

– One IR reflector. I used an A4 sheet of 10mm Styrofoam with aluminium foil attached with spray adhesive.

– One IR window. I built an A4 size “picture frame” of 10mm square balsa wood strips and stretched cling film over it.

– One 1 litre measuring jug

– Two small identical computer fans. I used Suron 50mm centrifugal blowers powered by a 6v gel cell battery

– Extra cling film

– Optional extras – kitchen timer, an A4 ”dark cool sky” panel of matt black aluminium with peltier cooling, glamorous lab assistant of choice.

image

What to do –

– Position probe thermometers in identical positions in both water containers. I placed the tips 10mm below the water line by drilling force fit holes in the sides of the containers.

– Position IR reflector and IR window 50mm above either water container. You may need to build two Styrofoam side walls, but air must be free to move over the surface of the water. (The use of the IR window is to ensure that air flow is similar over each water container.)

– Position the computer fans to blow across the water surface of each container, but do not turn on.

– Fill jug with warm water, stir, then fill each water container from the bucket. I used water around 40C as the ceiling was around 18C not a 3k sky.

– When and equal amount of water is in each container, turn on the computer fans.

– Observe the temperature change over time for each tank. Less than half an hour is required for such a small amount of water. You should observe that both tanks cool a the same rate (TEST A).

– Now the important bit – Repeat the experiment, but this time lay a small sheet of cling wrap on the surface of the water in each water tank. This allows cooling through radiation and conduction but prevents evaporation. You do not need the computer fans on in this test. You should be able to observe that while both containers cool slower than before, water under the IR reflector cools slowest (TEST B).

image

Interpretation –

In TEST A the water cools more quickly, however the two water containers temperatures remain very close to each other over time. This indicates that backscattered LWIR has a very limited effect on the rate of cooling for water when it is free to evaporatively cool.

In TEST B both water containers cool more slowly than test A, but a divergence in temperature between the two water containers is readily detectable. The container under the foil sky cools more slowly than that under the cling wrap sky. This indicates that backscattered LWIR from a warm material can slow the rate at which that material cools, if radiation and conduction are the only methods for cooling.

Test A represents the evaporative cooling conditions in the real oceans. Test B represents how the climate scientists have modelled the oceans with regard to backscattered LWIR. From what I have observed, backscattered LWIR can slow the rate at which substances cool. However in the case of liquid water that is free to cool evaporatively this effect is dramatically reduced. It would appear that including the oceans in the percentage of Earth’s surface that could be affected by backscattered LWIR may be a serious error. Earth’s oceans cover 71% of the planets surface. If backscattered LWIR cannot measurably affect liquid water, then CO2 cannot cause dangerous or catastrophic global warming.

I have conducted further tests using a “cold sky” panel cooled with ice water over the top of the cling film IR window. While the temperature divergence in the evaporation restricted test B does not appear faster, it does appear to diverge for longer.

I would encourage others to conduct similar empirical experiments and share their observations. I would be interested in comments in further experimental design, or empirical evidence related to the LWIR question.

Typical TEST A

Time Cling Wrap Screen Foil screen
0 37.1 37.1
5 33.2 33.2
10 29.4 29.4
15 27 26.9
20 25.5 25.5
25 24.5 24.5

Typical TEST B

Time Cling Wrap Screen Foil screen
0 38.2 38.2
5 36.3 36.6
10 34.8 35.3
15 33.5 34.2
20 32.6 33.4
25 31.5 32.6
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Stephen Wilde

One can go a step further and propose that the pressure of the atmosphere on the ocean surface sets the energy cost of a given amount of evaporation and thereby allows our oceans to regulate atmospheric temperatures as discussed by me in some detail here:
http://climaterealists.com/index.php?id=7798
“The Setting And Maintaining Of Earth’s Equilibrium Temperature “

“This paper outlines an idea or hypothesis that should be discussed. This idea has the huge advantage of being supported by all the available data both from over the last thousand years or more, the last 60 or 70 years and the last 20 years.”
“Mike Gene’s 10 signs of intellectual honesty:
1. Do not overstate the power of your argument. One’s sense of conviction should be in proportion to the level of clear evidence assessable by most. If someone portrays their opponents as being either stupid or dishonest for disagreeing, intellectual dishonesty is probably in play. Intellectual honesty is most often associated with humility, not arrogance.”

richard verney

I am one of those who have yet to be persuaded that LWIR can heat the oceans, or even reduce /slow down the heat loss from the oceans. I will expand, in a later comment, on some of the problems that appear to arise with LWIR and the oceans.
There are a number of reasons why high energy SWIR and lower energy LWIR may have different impacts upon the climate, not least the place within the system where the power is absorbed. For example, if 1 watt per metre squared of LWIR cannot penetrate the oceans to any significant depth, but instead remains in the atmosphere, then the effect of this may be different to 1 watt per metre squared of SWIR which penetrates the ocean to depth and thereby heats the oceans with ocean currents distributing that heat polewards.

Richard111

“I have attempted to mount a case for the idea that a given LONG WAVE GHG forcing will have considerably lower temperature response than a similar SHORT WAVE solar forcing.”
My layman observation, high humidity plus clear sky plus sunshine equals rapid air temperature rise. (short wave solar forcing) Conversely, high humidity plus clear sky and NO sunshine equals rapid temperature drop. (long wave GHG forcing). I have noticed the RATE of temperature change seems to follow the humidity level. See here: http://www.shadowchaser.demon.co.uk/eclipse/2006/thermochron.gif
Sadly, humidity level is not specified but sea is not far away, also land is arable.

JohnB

[snip off topic garbage -mod]

“It is, also, likely that the restoration of the flux imbalance at the TOA is quicker for a perturbation in GHG forcing than it is for a similar perturbation in solar forcing.”

That perturbation would occur overnight, right?
If so, it would be worth mentioning that fact.

Stephen Wilde

If anyone reads my earlier essay from 2011 please note that I consider the comment about atmospheric composition being relevant to atmospheric temperature in the absence of oceans to be erroneous. It would be relevant to the circulation but not to the temperature which is determined by mass not composition.

THIS is the experiment Bill Nye should have performed.

Realist2

“It is an intriguing possibility that both sides of the Global Warming debate could be correct to some extent.”
This is a sloppy generalization. It’s an attempt to be diplomatic, but it sloppily lumps every argument about climate into two categories, then assumes that everyone’s disagreement revolves around this singular point.

Kasuha

I would propose Test C: same as test A, but the air above the water is prevented from escaping and mixing with rest of the air in the room (i.e. the cover is airtight and the fan is inside). This would lead to evaporated water accumulating in the “atmosphere” instead of escaping to “free space” where it stops being part of the observed system.
I did not do this experiment but I would expect its results to somewhere in between your test A and B, suggesting that the effect of radiation may not be as negligible as you’re trying to suggest.

davidmhoffer

Thanks for the experiment, interesting. That said, there is a far more fundamental flaw in the sensitivity calculations.
A change in solar forcing adds energy to the system as a whole. A change in ghg forcing adds precisely 0 energy to the system as a whole. It only re-distributes the energy within the system. The IPCC even admits this when they say:
Surface forcing has quite different properties than RF and should not be used to compare forcing agents (see Section 2.8.1).
http://www.ipcc.ch/publications_and_data/ar4/wg1/en/ch2s2-2.html
So they speak out of both sides of their mouths, first arriving at a calculation that is defied by the actual physics and then quietly admitting so in another part of their publication.

John West

Sorry, lost interest @ “the enormous increase in Long Wave GHG forcing that has occurred in the last 60 or 70 years”; characterizing a theoretical (less than) 1% increase in LW heat flux as “enormous” and attributing it to GHG without sufficient evidence just doesn’t instill confidence in the author’s sense of scale and reason.
Some facts:
Theoretical increase in down-welling LW radiation from 2XCO2 = 3.7 W/m2.
Approximate average down-welling LW radiation = 333 W/m2.
Evidence for GHG attribution to warming: Hot Spot: …. missing. & Stratospheric cooling: …… 15+ year hiatus.

alex

ROFL.
The guy has no idea what energy means.

Stephen Wilde

“the enormous increase in Long Wave GHG forcing that has occurred in the last 60 or 70 years”
I think that statement is a serious flaw.
In fact we have previously seen that all the observed warming could have been caused by a reduction in global cloudiness when the sun was more active, the jets more zonal and the climate zones more poleward.
That process is now in reverse despite increasing CO2.
Any long wave forcing that may have occurred was when that shortwave came out of the oceans again in longwave form via enhanced El Nino events.

Matthew R Marler

This paper outlines an idea or hypothesis that should be discussed. This idea has the huge advantage of being supported by all the available data both from over the last thousand years or more, the last 60 or 70 years and the last 20 years.
Maybe, but you have not shown that. You need a review of all such evidence, and a showing that your hypothesis actually explains the evidence. The experiment itself is nice enough, but it supports a more limited claim.
What would be helpful would be a long time series with Earth mean temperature changes and the changes in concomitant solar irradiation by spectral bands, and a showing that the changes in Earth mean temperature correlate more highly with the changes in short wave radiation than with the changes in long wave radiation or TSI.

Watcher

The hypothesis proposed above seems reasonable– but only so long is it can backed by verified and verifiable science. Verifiability is the key.
It must be stressed–especially on this website where myths run so rampant– that the preponderance of evidence is still far, far in favor of the AGW theory. Thus far, the science, for all practical purposes, is settled. (Being science, it is always open to unsettling or upsetting with sufficient evidence.)
I and many others have observed that skeptics often grasp at a straw or two and consider it proof against human caused global warming. That is called cherry-picking the evidence. (More about that later.) Three or four black straws in a massive pile of yellow hay do not constitute evidence that totally upsets a tested and retested theory explaining the color of the massive pile.
I see several problems with the paper above:
First, it is part science and part supposition that has not been verified by similar studies. Although it uses science in part to make its suppositions–which gives it the feel of authenticity and correctness–it may or may not be the appropriate science, or it may not consider all relevant factors. Only upon verification and validation by others qualified in the relevant fields could it be considered scientifically valid.
Second, it is politically oriented. Why was the word “alarmist” used? In a scientific paper there’s no place for such a term. “Alarmist” is pejorative because it assumes– without reasonable evidence–that those who have studied global warming and say it is human-caused are for some unreasonable purpose promoting it or consequent alarm in response. Nothing could be further from the truth. Scientists who study the phenomenon are alarmed because the facts *are* alarming. and I obviously with good reason. Global warming looks like the most devastating natural event that has been happening to our planet other than the very real possibility, however remote, of a huge meteor strike. It certainly is happening and has been happening for about 150 years. That is undeniable. Second, it is almost undeniable that human causes have created the spike in warming.
The author is personally biased against those who propose that global warming is human-caused. Use of the term alarmist is intended to cast doubt on verified scientific findings and those who investigate and support those findings. Again, in the strongest of terms, this paper is not promoting only science, but politics as well. Promotion of politics in a paper purporting to be scientific dilutes its intended positive effect and casts doubt on the intentions of the author.
Third, it is not reasonable to accept this statement as true (although many readers here will do so automatically):
“The sceptics, on the other hand, are fairly obviously quite correct when they say that the high sensitivities postulated by the alarmists do not fit with the measured temperature record of the 20th and 21st century.”
It is well known among statisticians and scientists that 15 or 20 years of climate measurement does not make a scientifically valid trend. Skeptics have cherry-picked evidence over such a short period and claimed it is proof the temperature is not rising in the long term. The global temperature may or may not be rising. But it is impossible to know until 30 or more years passes, in order to compare with past trends.
Therefore the statement above uses cherry-picked evidence to make an unverifiable claim. And this is supposed to somehow validate skeptics’ arguments? this claim highlights the main problem with most skeptics claims: they’re unverified and/or unverifiable. And they rely on cherry-picked evidence or evidence that has already been demonstrated as invalid or flawed. Until anyone’s arguments, however much science-based (it may be the wrong science or the right science wrongly applied), are validated by verified and peer reviewed science as noted in the first point, above, they are only hypotheses or supposition, not science.
Remember, this is not about winning an argument. It is about finding enough science and the right science to unequivocally reveal what is happening to our environment.
If, despite the obvious flaws in the paper above, it leads to new evidence regarding global warming, bravo! If it doesn’t, then we’ll see it is just another straw to grasp for those who are afraid of the undeniable reality of human caused global warming.
So far the *best* evidence reveals humans *are* causing catastrophic global warming, it is something to be alarmed about, and we should be doing all we can to change it.
Perhaps *more* importantly, even if AGW were not happening, we should *still* do all we can to reduce our impact on the planet as much as possible.

Watcher:
At April 21, 2013 at 10:36 am you suggest

Perhaps *more* importantly, even if AGW were not happening, we should *still* do all we can to reduce our impact on the planet as much as possible.

I disagree completely.
Firstly, as a matter of fact, AGW is not happening. Global warming was last century.
Secondly, as a matter of opinion, the world would be a much better place if we could mitigate effects of weather, earthquakes volcanoes and disease, if we could convert wastelands to productive regions which benefit people, and if we could more efficiently utilise natural resources. This is because I value people more than stones, plants, animals and microbes.
Richard

Bart

davidmhoffer says:
April 21, 2013 at 9:30 am
“A change in solar forcing adds energy to the system as a whole. A change in ghg forcing adds precisely 0 energy to the system as a whole.”
Not necessarily. A change in solar forcing increases the time rate of change of energy coming into the system. A change in ghg indeed provides zero increase to the input time rate of change, but it could momentarily decrease the time rate of change of energy exiting the system, leading to additional accumulation of energy (notwithstanding that observations indicate that a change in CO2 does not appreciably do so in the current climate state).
Energy and the time rate of change of energy (aka, power) are two different things. A lot of misconceptions about the system arise from this confusion. The radiation flow in and out of the system is a continuous transport phenomenon, as is the flow of CO2 into and out of the surface system.
Watcher says:
April 21, 2013 at 10:36 am
“It must be stressed–especially on this website where myths run so rampant– that the preponderance of evidence is still far, far in favor of the AGW theory. “
Not even close. The preponderance of cherry-picked evidence by advocates only.
“Skeptics have cherry-picked evidence over such a short period and claimed it is proof the temperature is not rising in the long term.”
As have the advocates cherry picked data over an only slightly longer term.
The global temperature may or may not be rising. But it is impossible to know until 30 or more years passes, in order to compare with past trends.”
An arbitrary interval with no meaning. Given the ~60 year cycle readily apparent in the temperature records, 30 years is approximately the worst possible inteval to select.

DocMartyn

we sometimes need to shine light in to a cell culture, for measuring oxygen generation in photosynthetic organisms, or to perform photochemical action spectra.
Essentially all you need do is shine a bright light into your sample and we typically used a slide projector. However, if you use the light from a 3300K tungsten filament lamp you sample cooks as the output of the lamp is mostly IR.
http://zeiss-campus.magnet.fsu.edu/articles/lightsources/images/tungstenlampsfigure1.jpg
We used to use a cool-light by passing the beam through a round bottomed flask of water. This lens gives you a power beam of white light and almost completely attenuates the IR. The pathlength of the water is only 10-15 cm, but that is enough to stop almost all of the IR from a powerful light source.
My guess is that if you has a diffraction grating and dialed your wavelength, an iris and used a pyrometer to measure your output you could examine the amount of sensible heat that you get upon illuminating a body of water.I suspect that blue light gives sensible heating and IR mostly latent heating.

I suggest that an equipment list be printed, each item incorporating a link to an Amazon page where it can be bought, along with an ASID (Amazon stock ID number). Each item’s cost should be noted. This would encourage high school students and others to repeat the experiment.

Manfred

This may be supported by temperature obeservations:
Since the 1980s, temperatures over land increased much faster than over sea.
But they increased/decreased at the same rates before, particularly during the increase between 1915-1947.
http://www.woodfortrees.org/plot/crutem4vgl/mean:10/plot/hadsst2gl/mean:10
They also increased at the same rates in the lower troposhere measured by RSS/UAH data since 1979.

joeldshore

Interestingly, Idso 98 uses real world experiments that, largely, do apply to GHG Forcing and their climate sensitivity is considerably lower than the IPCC’s consensus.

“Largely” as in the sense, “except for those that don’t” like “Natural Experiment #3” on the seasonal cycle or “Natural Experiment #5” on the equator-pole temperature gradient due to the gradient in solar radiation? ( http://www.warwickhughes.com/papers/Idso_CR_1998.pdf ) No, the reason that Idso gets low climate sensitivities is because that is what he wanted to get and his analysis of his “natural experiments” is naive in the extreme. As an example, in Natural Experiment #4, Idso considers the gross downward flux due to GHGs, not the net, and ignores the fact the he is treating all of the GHGs as forcings and none (i.e., the water vapor and clouds) as feedback.
I find it amusing that a contribution like this is published here on WUWT with no sense of self-awareness or irony. After all, if climate scientists tried to claim that the efficacy of longwave forcing was much larger than that of the shortwave forcing, we all know what the response of people here would be. (In fact, even though the climate scientists do not do that, this does not stop people from making completely false claims that somehow the positive feedbacks act only on forcing due to CO2 and not due to solar or other forcings.)

Reich.Eschhaus

Home experimentation! I like that!
You could have a point if you could define a mechanism whereby the Long Wave GHG Forcing impacting the ocean surface is transmitted out of the earth system into space.
For the moment I have to agree with Kasuha in that you need an experiment with an atmosphere on top of the experimental set-up. If that’s too complicated to do in a home experiment, you might want to think about a method to measure the rates of evaporation in Test A.
If there would be increased evaporation from Long Wave GHG Forcing this would transfer the energy of the forcing to the water vapour which for a substantial part would return back to ocean by means of rain (directly on the ocean, or via land and rivers; not if it ends up in a lake or gets added to permanent ice sheets).
Hope you get my drift, looking forward to seeing more experiments!

William Astley

Idso 98 has a case that shows the ocean’s sensitivity to a change in forcing is 0.071°C/(W m–2) based on measurement not theory.
A possible explanation for how long wave radiation warms the ocean is there are significant and almost constant winds over the ocean, which in turn creates turbulence. The water molecules on the surface of the ocean therefore are constantly changing which distributes the energy in the upper surface of the water.
The estimate sensitivity to a change in long wave forcing for the ocean is 0.071°C/(W m–2).
CO2-induced global warming: a skeptic’s view of potential climate change by Sherwood B. Idso
(See below for a link to the Idso paper’s abstract and a link to the paper. I would high recommend a re-read.)
http://www.int-res.com/abstracts/cr/v10/n1/p69-82/
2.10. Natural Experiment 8
A final set of empirical evidence that may be brought to bear upon the issue of CO2-induced climate change pertains to the greenhouse effect of water vapor over the tropical oceans (Raval & Ramanathan 1989, Ramanathan & Collins 1991, Lubin 1994). This phenomenon has recently been quantified by Valero et al. (1997), who used airborne radiometric measurements
and sea surface temperature data to evaluate its magnitude over the equatorial Pacific. Their direct measurements reveal that a 14.0 W m–2 increase in downward-directed thermal radiation at the surface of the sea increases surface water temperatures by 1.0°C; and dividing the latter of these 2 numbers by the former yields a surface water temperature sensitivity factor of 0.071°C/(W m–2), which would imply a similar surface air temperature sensitivity factor at equilibrium.
By comparison, if I equate my best estimate of the surface air temperature sensitivity factor of the world as a whole [0.100°C/(W m–2)] with the sum of the appropriately-weighted land and water surface factors [0.3 0.172°C/(W m–2) + 0.7 W, where W is the surface air temperature sensitivity factor over the open ocean], I obtain a value of 0.069°C/(W m–2) for the ocean-based component of the whole-Earth surface air temperature sensitivity factor, in close agreement with the results of Valero et al.
The very conservative and likely to high estimate (as there is no tropical tropospheric hot spot) for the theoretical increased forcing due to a doubling of atmospheric CO2 is 4 W m–2.
Idso’s best estimate sensitivity is 0.10°C/(W m–2), which produce 0.4 °C warming for a doubling of CO2.
As there is no tropic tropospheric hot spot the actual forcing change could be significantly less (say wag it at half?). If one assumes the CO2 forcing is say 2 W m–2 (reducing by half as there is some physical reason why there is no tropic tropospheric hot spot.), then the warming due to a doubling of atmospheric CO2 could be around 0.2 °C.
If the above assertions are correct, then a majority of the 20th century warming has caused by non greenhouse gas warming.
It appears we are rapidly approaching the period when the planet will cool, at which time observations will assist with the correction of obvious scientific mistakes as well provide an explanation as to how solar cycle changes can cause the planet to warm and cool.
http://www.climate4you.com/images/GISP2%20TemperatureSince10700%20BP%20with%20CO2%20from%20EPICA%20DomeC.gif
Comments:
High altitude cloud (cirrus) are also modulated by ions. There are less cirrus clouds when ions in the troposphere increases and more cirrus clouds when ions decrease. I have not seen a published explanation as to how cirrus ion modulation mechanism works but a thought would be an increase ions results in larger crystals that are no longer supported in the atmosphere.) High altitude cirrus clouds warm the planet particularly in high latitudes regions in the winter by the greenhouse effect.
As noted solar wind bursts remove cloud forming ions via the mechanism electroscavenging. (Solar wind bursts create a space charge differential in the ionosphere.) Solar wind bursts normally occur when the solar cycle is high and therefore due not affect cloud modulation as the solar heliosphere is strong which deflects GCR which also results in low ions. However at the end of solar cycle 24 there were very large frequent CME which created solar wind bursts.
As noted for some unexplained reason the north magnetic pole drift velocity increased mid 1990 (coinciding with the start of the warming period) by a factor of 4 to 5 from 10 to 15 km/year to 50 km/year. The geomagnetic specialist hypothesized a hidden north pole magma plume that suddenly started up as on explanation. As there are cycles of abrupt changes to the geomagnetic field that coincide with solar produced cosmogenic isotope changes, the sun should be on the suspect list. As it appears solar magnetic cycle 24 is an interruption to the solar magnetic cycle perhaps we will have a chance to resolve this problem by observation.

Greg House

Guest post by Bob Irvine: “I have attempted to mount a case for the idea that a given LONG WAVE GHG forcing will have considerably lower temperature response…
…What follows is an edited version of the experiment design and results as posted on the WUWT thread. I would encourage others to conduct similar experiments…”

=========================================================
Your GHG forcing is also known as “greenhouse effect” and as presented by the IPCC, the back IR radiation from the so called “greenhouse gases” should warm the source of radiation, namely surface (http://www.ipcc.ch/publications_and_data/ar4/wg1/en/faq-1-3.html). A an sorry to disappoint you, but such an effect on the temperature of the source of IR is physically impossible. Even on the theoretical level such an effect must lead in some cases to an endless mutual warming without additional energy input, which is absurd.
To your experiment, I told you some time ago (http://wattsupwiththat.com/2013/04/05/a-comparison-of-the-earths-climate-sensitivity-to-changes-in-the-nature-of-the-initial-forcing/#comment-1267467) that your result did not prove any “greenhouse gas” forcing or “back radiation forcing”, because the slowing down of the cooling rate can be explained by suppressed convection due to differences in covers. I remember your reply, where you recommended another “experiment”, namely holding something 2cm close to the cheek and seeing the result of “back radiation warming”. Then I told you that it would be suppressed convection as well. It is very sad that you just can not get it, it is actually a middle school stuff.
The solar forcing is real, “greenhouse gas forcing” is not, it is a fiction. A real CO2 effect (in it’s present concentration) due to his well known thermal properties would be like 0.0001C. It can also contribute to cooling by preventing some solar IR from reaching the surface. But again, no warming/slowing cooling back radiation effect as presented by the IPCC is physically possible.

Reich.Eschhaus

Something I forgot to mention. The comparison of present temperatures and the IPCC’s predicted equilibrium states is silly. It takes some time to reach the equilibrium state. If I want to boil an egg for breakfast, I put a pan of water on the cooker and turn up the forcing. I predict the water temperature will reach it’s equilibrium state at 100º C (actually this depends on air pressure as well). It will take some while however (depending on starting temperature, volume, forcing and the rate in which the pan+water looses energy to the greater kitchen environment). 😉

jorgekafkazar

John West says: “Sorry, lost interest @ “the enormous increase in Long Wave GHG forcing that has occurred in the last 60 or 70 years””
John, I didn’t get past “This idea has the huge advantage…”
The idea needs a lot of further work. I suspect there’s much of value therein, but the writing is too over the top.

“top fraction of a millimetre of the ocean is heated up by the Long Wave Radiation”
Are there no waves or turbulence on the ocean in your conceptual model? Bit of an oversight.
“sensitivities calculated from the Last Glacial Maxima (LGM) or volcanoes are essentially based on Solar Forcing”
Not true. The change in the concentration of greenhouse gasses between the glacial and the interglacial is one of the largest forcing factors (though not the prime mover).

geran

Yes, I will have to try the experiment–thanks for the info.
Long wave vs. short wave, such a hard concept to factualize. The reason is that the temperature of the “receiving” body is in play. Sea surface water molecules receive or reflect IR based on their initial temperature. It’s so confusing….

RERT

Mosher –
Nice touch that Mike Gene’s ode to humility is sweeping and arrogant. Must be another of those ‘humour’ things that got a recent post so confused.
That said, I think what we have in the post is a fairly naive writeup of a great idea, namely that an assumption that climate sensitivity is the same for all forcing types is probably false. This really does deserve some attention.

Reich.Eschhaus

@RERT
“That said, I think what we have in the post is a fairly naive writeup of a great idea, namely that an assumption that climate sensitivity is the same for all forcing types is probably false. This really does deserve some attention.”
No! It is just an idea! I can have ideas on all kinds of things. Doesn’t make ‘m true. If there is no mechanism proposed for why the energy of LONG WAVE GHG forcing impacting the ocean surface is ditched into space faster than the energy of SHORT WAVE solar forcing, then “an idea’ is all that it is.

Rob R

A few years back when Willis was outlining his global-scale Steel Greenhouse model there was some discussion of the relative effectiveness of solar (short wave) vs greenhouse (longwave) forcing of temperature. My impression was that the efficacy of a change in solar forcing was shown to be about 1.6 times that of a change in greenhouse gas forcing. Solar adds heat to the entire system, but with greenhouse forcing there are losses that reduce its effectiveness. Someone with a better memory might like to comment further.

rgbatduke

temperature of the source of IR is physically impossible. Even on the theoretical level such an effect must lead in some cases to an endless mutual warming without additional energy input, which is absurd.
Or, as anyone with a shred of knowledge of actual mathematics and the laws of thermodynamics can easily show, when the object being “warmed” is actually being warmed by a heat source like Mr. Sun, it never overtly leads to a runaway solution, violation of the first law (energy conservation) or violation of the second law (entropy increase for irreversible processes). On the contrary, one can show quite easily that a sphere heated by the sun and cooled by outgoing blackbody IR radiated to space as a cold reservoir will “warm” if one interpolates an layer of gas that is opaque/absorptive in (bands in) the outgoing IR, in the specific sense that its dynamical equilibrium temperature will increase. One can show that at no time is energy conservation violated. One can show that entropy of the Universe is increased by the net heat transfer(s) involved in the process. One can do this with elementary physical and thermodynamic arguments.
Leaving out the source of heat as you implicitly do in the statement above is of course going to get you in trouble. You should listen to Bart, above. It’s easy to get these things wrong.
rgb

John Finn

Greg House says:
April 21, 2013 at 1:48 pm
Guest post by Bob Irvine: “I have attempted to mount a case for the idea that a given LONG WAVE GHG forcing will have considerably lower temperature response…
…What follows is an edited version of the experiment design and results as posted on the WUWT thread. I would encourage others to conduct similar experiments…”
=========================================================
Your GHG forcing is also known as “greenhouse effect” and as presented by the IPCC, the back IR radiation from the so called “greenhouse gases” should warm the source of radiation, namely surface (http://www.ipcc.ch/publications_and_data/ar4/wg1/en/faq-1-3.html). A an sorry to disappoint you, but such an effect on the temperature of the source of IR is physically impossible. Even on the theoretical level such an effect must lead in some cases to an endless mutual warming without additional energy input, which is absurd.

Greg
Many WUWT readers will recognise the flaw in your argument and will probably ignore it, but the problem is that AGW advocates see your comment and present it as typical of the sceptic position.
Let’s make this as simple as possible.
The earth receives a ‘constant’ source of energy from the sun. In order to maintain a stable temperature the earth (and it’s atmosphere) must get rid of (or emit) an equivalent amount of energy. If the rate of energy emission from the earth is reduced then the earth will heat up.
There is no “endless mutual warming “. The warming is from the sun. The earth then warms and emits energy to space. Eventually there is an equlibrium whereby the incoming energy is in balance with the outgoing energy. This is basic thermodynamics. ‘Greenhouse gases’ reduce the rrate at which outgoing energy is emitted to space. The earth will therefore warm until the incoming/outgoing balance is restored.

Cynical Scientst

My comment is that the system in your experiment isn’t sealed. You are blowing air across the water with a fan and the heat extracted in this way is venting back into the room. The water with the backscattered LWR is receiving more heat into a thin surface layer. Unsurprisingly the forced convention via the fan immediately extracts almost all of this extra heat into the air. The air coming off the backscattered LWR container will be fractionally hotter and more humid than the air coming off the other container. That is where the heat is going.
Your experiment does not support the contention that backscattered LWR causes no heating over the 71% of the globe which is covered by water, which is the spin you seem to be trying to put on it. What it suggests is that the main effect of backscattered LWR over water is not to heat the water itself, but rather to heat the air above the water. The heat goes somewhere. Over the oceans it goes into making the air fractionally hotter and more humid.
This does however underline just how difficult it is going to be for Trenberth to come up with any plausible explanation for how his ‘missing heat’ from the greenhouse effect is ending up in the deep ocean where he says it is. Your experiment underlines the fact that you simply can’t heat water from above with LWR if it is exposed to convection because the heat goes straight into the air.

Watcher:
This is quite a settled science : no one in the AGW camp can provide a scintilla of data that
settles anything. If the issue were settled, there would exist models capable of accurate prognostications. There are none, so the AGW extremists are simply left to proclaim the issue settled. In fact, I know of few, if any, scientific disciplines which have settled their primary issues. In the past many disciplines thought they had figured it all out, and considered the science settled,
only to find out later how wrong they were. In terms of logic, a science can never “prove” that
any of its theories are correct : that would require affirming the antecedent, an impossibility.
And as for changes to the Earth, exactly why do you think you are either qualified or have been
empowered to make judgments?

Joseph Bastardi

I truly believe there are alot of people that dont want this argument to ever end because it brings them attention and status. I for one am tired of it, I was born to forecast weather, but knowing the climate is essential in providing a base for a good forecast. Its no different than a general understanding past battles or the enemies tendencies in previous fights. People want to dismiss such things today, but all we see now is the similar events in the past observed much more intensely. So I have proposed a simpler test. Look at the global temp in 1978 when the PDO flipped to warm and the satellite era of objective temp analysis truly started, and see what it is in 2030 now that pdo has flipped to cold and the atlantic will follow in about 10 years. So far the triple crown of cooling, introduced on Oreilly 4 years ago along with this test proposal to Bill Nye seems to be carrying the day, as seen here:
http://models.weatherbell.com/climate/cfsr_t2m_recent.png
The sun, the oceans and stochastic natural events rule the climate. I am sorry if that destroys alot of arguing but I have proposed the test and its running and in the end I am confident of the result. Most likely when dealing with the massive power of the sun, and then the earths reaction, the simple, most obvious answers are most likely correct. Man is just not as important as many believe he is, IMO. If that lessens my “status” in this debate, so be it. The whole thing we be proven to be an overblown sham that wasted alot of time and money in a world that needed it in other more dire places

Rob JM

Big Problem, Short wave climate sensitivity is not high at all!
You have made a massive assumption that Solar TSI is the forcing responsible for the temp change without considering the much larger forcing from cloud changes.
In the satellite period we have observed a 5% decrease in cloud cover between 1987 and 2000.
This is a 0.9w/m2 forcing (after adjusting for increases OLR) and caused only 0.3 deg C of warming.
Climate sensitivity for a shortwave forcing is therefor less than 0.4
The question on whether sensitivity is the same for different forcing types is still valid, Its just that in this particular instance both sides have clearly been wrong!

Tom Jones

I hate to be a bucket of cold water, but I really doubt there is any proof whatsoever that will convince the true believers. Max Planck once quipped, “Science advances one funeral at a time”. The objective is not to win an unwinnable argument. The objective is to prevent committed zealots from getting the government to do something that is very expensive and totally useless.

Henry Clark

“There is a lot of evidence from the Last Glacial Maxima and Volcanoes and other areas that climate sensitivity is quite high (about 0.8, i.e. requil. T=0.8xrF). Certainly, this can be seen on geological scales. These estimates are based on Short Wave Solar Forcings. The trouble starts when they try to apply these high sensitivities to the enormous increase in Long Wave GHG forcing that has occurred in the last 60 or 70 years. They mistakenly assume that a given GHG forcing will have the same equilibrium temperature response as a similar Solar Forcing and then find it difficult or impossible to make the meagre temperature response over recent years fit their high sensitivities.”
The first part neglects how total solar-related forcing, including fluctuation in the sun’s interplanetary magnetic field impacting cosmic ray flux and indirectly Earth’s albedo via cloud cover change, is around 3 to 4 times as many W/m^2 as that of variation in more near-constant sunlight (TSI) alone, and looking at the total correspondingly drastically drops the climate sensitivity seen. Illustrations include blatant correlation of GCR variation with medium altitude humidity in http://s7.postimg.org/69qd0llcr/intermediate.gif , Dr. Shaviv’s estimate of a 4x ratio in http://www.phys.huji.ac.il/%7Eshaviv/articles/2004JA010866.pdf discussed at http://sciencebits.com/OnClimateSensitivity , and a good intro in general at http://www.space.dtu.dk/upload/institutter/space/forskning/05_afdelinger/sun-climate/full_text_publications/svensmark_2007cosmoclimatology.pdf .
The only realistic explanation for this lack of correlation ( FIG, 1) is that the IPCC’s sensitivities are far too high and that the “Effective Radiative Forcing” for Long Wave GHGs is considerably lower than the “Effective Radiative Forcing “ for Short Wave solar.
Or, like Rob JM just noted, the W/m^2 figure used for short wave solar variation is too low effectively by not counting indirectly-caused cloud cover change, as prior links illustrate.
This thread’s article, for unclear reason, is more or less like the last one at http://wattsupwiththat.com/2013/04/05/a-comparison-of-the-earths-climate-sensitivity-to-changes-in-the-nature-of-the-initial-forcing/ except missing some of the better illustrations in the prior article, while not having an improvement to the experiment like removing the thick styrofoam backing from the aluminum foil as my comment there suggested.
Maybe I should try submitting an article.

davidmhoffer

Bart;
Not necessarily. A change in solar forcing increases the time rate of change of energy coming into the system. A change in ghg indeed provides zero increase to the input time rate of change, but it could momentarily decrease the time rate of change of energy exiting the system,
>>>>>>>>>>>>>>>>
Well certainly. But this is a temporary condition as you yourself state. In a theoretical “doubling of co2” we might even be able to quantify it and measure. For practical purposes though, we’re only increasing CO2 at a rate of 2 ppm per year. The heat capacity associated with such a small change is miniscule. So technically I agree with you, I just don’t see it as being significant in the climate context.

Bart

davidmhoffer says:
April 21, 2013 at 7:16 pm
“But this is a temporary condition as you yourself state.”
It is temporary because an increase in retained heat would increase the outward bound radiation until the net energy making it past the barrier balanced that coming in.
As I stated though, there is no apparent significant dependence of global temperatures on CO2 in the climate data , so you are probably right about that. In fact, the data indicate the converse, that atmospheric CO2 concentration is almost entirely dependent on temperatures, and so I disagree that “we” are increasing CO2 at 2 ppm/year.

Rob

Some fairly clear biases in outlook and in the strength of conclusions on one test, to be fair. And looking at the linked ‘irrelevant’ study I’m not sure that it was, I’m wonder if someone could explain why it would be so? However it would appear that the level of investigation on this basic question by warmers is at least matched by this. Even if valid their linked test was done as something of a lark. Wouldn’t it be fun to take a look as to how the proposed CO2 effect on warming affects oceans? Yes, it would be fun – it might even be science…

Rob

*I wonder

Alec M

For heaven’s sake, there is no net LW forcing. The operational emissivity [radiation only] is ~0.4, 1/3 rd minor side-bands and trace gases, the rest the atmospheric window. Taking account of the convection and evapo-transpiration, the average earth emissivity is 63/396 = 0.16, and you predict this exactly using standard physics.
The main GHG bands including CO2 switch off that net emission. This is radiative physics equilibrium 101.
Because of this error by the meteorologists mistaking the S-b output of pyrgeometers for a real energy flux, we have wasted 10s of billions on stupid science.

george e. smith

Well the issue of warming air or warming ocean is one that gets a lot of attention.
Case in point; the local PBS T&V stations in the SFBay area; ch-9 and ch-54, have both now gone to a 24 hour, 365 days a year money cadging program schedule. All they run, is some lecturer or other, talking about your yoga exercises, and medication pills, or else they have an obviously senile Bill Moyer, listening dumbfounded to some nutcake or oth , rtalking about their latest readers digest article or book maybe.
So for about the last month, pbs has been begging us to watch Moyer trying to make sense out of the monotonous utterances, of some supposed biologist, who is now a climate expert, and also an expert on chemical toxicity. She complains that the EPA only regulates a few hundred chemicals, out of the 80,000 chemicals used by industry, as to their toxicity to children or fetuses. Now she did not list which of these 80,000 chemicals are commonly fed to children or fetuses. Well she’s a biologist; not a chemist, so why doesn’t she complain about the millions of known plant species that are toxic to children or fetuses, and are not currently regulated by epa.
So this Sandra Steingruber, says that fracking rock structures miles deep for energy supplies, releases ozone and unburned methane into the atmosphere. I often fish a popular California lake, that is always venting unburned methane, that bubbles up through the water; and nobody is fracking that, or the rotting vegetation in arctic peat bog and permafrost areas.
Today she told Moyer; who lapped it up, that burning fossil fuels heated the air and the oceans, killing off many lifeform species.
Her book that she is pushing, is about raising her son. I don’t think she explained to Moyer, why; as an environmentally concerned biologist, she even allowed herself to have a son; knowing how overtaxed the earth’s resources are, by over population.
That this person, is so ill informed about how thermodynamics works to control heat flow, and about how radiation physics varies greatly with wavelength as to its interraction with earth materials, like water oceans, and common gaseous atmosphere.
Conduction and convection, act in concert, to prevent significant transfer of heat from the atmosphere to the ground or the oceans, and the absorption coefficient of water acts to prevent LWIR radiation, from transporting significant amounts of radiation energy from the atmosphere to the deep oceans; but promotes evaporative transport of latent heat from the ocean surface, to the upper atmosphere.
Moyer, just sits there, and never questions her assertons about the effect of energy exploration on the lives of children or fetuses. In general, the more energy, the more of those children and fetuses will get to actually have lives.

I also have to agree with Greg and others who see (most) of the heat of earth coming in via the water where the energy from the sun <0.5 um is the highest and where water absorbs, meaning most of that radiation is changed to warmth because there is mass. A (GH) gas has little mass, hence it deflects where it absorbs.!!
Most recently they also discovered CO2 absorbs at some places in the UV which is why they can identify it on other planets.
I don’t want to give the CAGW crowd more food for turning the whole CO2 scare into CAGC but I will explain it again to those who still "believe" in CO2 as being a factor in unnatural warming of earth by approaching it from another angle,
Check this graph:
http://en.wikipedia.org/wiki/File:Solar_Spectrum.png
The red is what you get on your head. Do you all get that? The yellow marked amount of radiation of that solar spectrum is what is being back radiated, to space, mostly by the O3, O2, HxOx and NxOx, and lastly also by CO2. This is why we are even able to measure it (ti.e. he absorption spectra of these gases) as it bounced back to earth from the moon. All these gases are GHG’s, agreed?
Now, do you understand that if there is more of these gases coming into the atmosphere, either naturally or man made, that more of it is being back radiated? If more is being back radiated it means that less radiation is coming in, the red part is becoming smaller, hence we are cooling. So, more GHG naturally means more cooling.
Hence the reason why I say that if you want to prove that the net effect of an increase in one particular GHG is that of warming rather than that of cooling you have to show me a balance sheet that would prove how much cooling and how much warming is caused by a certain% increase of that gas.
The problem is that science has stood still in this regard and has relied heavily on the closed box experiments – by Tyndall and Arrhenius-, and these only show the one side of the coin. The absorption of CO2 causing the back radiation to earth 14-16 um, is at around 200K, while the incoming radiation at 1-2 and 4-5 um being back radiated to space is around 5000K. Furthermore, as I have shown in an earlier post, there is little or no absorbency of water at 14-16 um so it (i.e. the 14-16 coming back to earth) cannot heat the water. Therefore, I am naturally inclined to think that the net effect of more CO2 in the atmosphere is that of cooling rather than warming.
Do you now see what the problem is?
I just hope that people are not going to see the current natural global cooling
http://blogs.24.com/henryp/2012/10/02/best-sine-wave-fit-for-the-drop-in-global-maximum-temperatures/
and turn it into some AGC or CAGC……..

Kristian

rgbatduke says, April 21, 2013 at 3:52 pm:
“On the contrary, one can show quite easily that a sphere heated by the sun and cooled by outgoing blackbody IR radiated to space as a cold reservoir will “warm” if one interpolates an layer of gas that is opaque/absorptive in (bands in) the outgoing IR, in the specific sense that its dynamical equilibrium temperature will increase.”
Yes, one can ‘show’ it theoretically using plain arithemtic and add the ‘back radiated’ flux from the absorptive gas layer to the sphere’s outgoing flux. But it is of course not what happens in the real world. Not if there is a vacuum separating the sphere and the gas layer so that only radiative heat loss comes into play. The layer would simply come in between the sphere and its cold reservoir, get warmed by part (half) of the absorbed heat flux and let the rest (the other half) escape to the cold reservoir. Just like a Carnot engine in a Carnot cycle, only the part of the heat flux from the hot reservoir ‘captured’ by the gas layer doesn’t lead to any mechanical work done, but rather to heating the layer itself:
http://user.physics.unc.edu/~rowan/p24site/p24units/unit18/FG18_16.JPG
(No heat ‘flowing’ back to the hot reservoir making it even hotter when the engine is heated. Only reduced heat loss to its cold reservoir. Where does the rest go? To do work. Or, as with the gas layer, into warming and maintaining its temperature.)
http://books.google.no/books?id=PfadZy35Wh0C&pg=PA442&lpg=PA442&dq=blackbody+sphere+surrounded+shell+radiation&source=bl&ots=TDbus0Dwu4&sig=3Aj5S6SlUB55MY9ry_MBXzTBm84&hl=no&sa=X&ei=d6VxUfOHC8Os4ASGsYCACQ&ved=0CEUQ6AEwBDgU#v=onepage&q=blackbody%20sphere%20surrounded%20shell%20radiation&f=false
(Problem 27. As you can see, the shell simply reduces the heat loss to space. It doesn’t heat its source, even when this is heated by its own source. I quote: “A sphere of radius R is maintained at a surface temperature T by an internal heat source (Figure 3).” It doesn’t say ‘PLUS the back radiation from the surrounding shell.
This is also how Multi-layer insulation on spacecrafts works:
http://en.wikipedia.org/wiki/Multi-layer_insulation
“The principle behind MLI is radiation balance. To see why it works, start with a concrete example – imagine a square meter of a surface in outer space, at 300 K, with an emissivity of 1, facing away from the sun or other heat sources. From the Stefan-Boltzmann law, this surface will radiate 460 watts. Now imagine we place a thin (but opaque) layer 1 cm away from the plate, thermally insulated from it, and also with an emissivity of 1. This new layer will cool until it is radiating 230 watts from each side, at which point everything is in balance. The new layer receives 460 watts from the original plate. 230 watts is radiated back to the original plate, and 230 watts to space. The original surface still radiates 460 watts, but gets 230 back from the new layers, for a net loss of 230 watts. So overall, the radiation losses have been reduced by half by adding the additional layer. More layers can be added to reduce the loss further.”

Frank

Bob: Your experiment may have several flaws. The surface of the “IR reflector” that is facing the warm water will be warmed by the water and the styrofoam may reduce the rate at which it transfers heat to the room. So the surface of your “IR reflector” could be warmer than the ceiling and walls of the room, which are radiating towards the water through your “IR window”. So your “IR reflector” could simply be acting likely a winter coat on a cold day – the inside of the coat is warmed by your warm skin (analogous to the warm water) and the insulation in the coat (styrofoam) slows down conduction of heat to the environment (the room).
When the fan is blowing, the surface of your IR reflector could be cooled by convection and be closer to the temperature of the room which is “shining” through the cling wrap. You should certainly try your experiment with and without the cling wrap while keeping the fan running in both cases, so that the only thing you have changed is evaporation.
You should also make your “IR reflector” as similar as possible to your “IR window” – two similar frames covered with cling wrap or aluminum foil. Since aluminum foil is thin and a good conductor, once you eliminate the styrofoam, your “IR reflector” should conduct and block convection more like your “IR window”.
The fact that thermal IR penetrates only the top few microns of the surface of the ocean turns out to be unimportant. Both the atmosphere and the ocean emit thermal IR, with the ocean emiting slightly more because it is usually warmer and has higher emissivity. All of the thermal radiation that leaves the water is emitted from the same few microns at the surface of the ocean. (If thermal IR can travel downward through only a few microns before being absorbed, thermal IR can’t get out unless it is emitted from the same few microns.) When you consider both the upward and downward flux (which both involve about 350 W/m2 of energy entering and leaving a very think layer), NET thermal IR makes the surface of the ocean cooler than the water just below. Evaporation – which also comes from the top layer of water molecules – also cools the top few microns. During daytime, some short wavelength solar radiation is absorbed by the top few microns, but the bulk of the energy is deposited in the top few meters. Without heat from the top few meters, the top few microns of the ocean would freeze, not boil of into the atmosphere. At night, loses by net thermal IR and evaporation cool the surface, making it dense enough to sink and convecting the water warmed by the sun to the surface. The bulk of the ocean is warmed by the sun and that energy is convected or conducted to the top few microns where it is lost by evaporation and radiative cooling – and those losses are far bigger than the thermal IR arriving from the atmosphere.